Thread-controlling attachment for sewing-machines



' No. 6|3,475. Patented Nov. I, I898.

F. H. RICHARDS.

THREAD CONTROLLING ATTACHMENT FOR SEWING MACHINES.

(Application filed Feb. 3, 1898.)

(No Model.)

Inventor:

Witnesses,"

THE udnmsprrzns coump-mu ma, WASHINGTON u c SNITED STATES PATENT OFFICE.

FRANCIS H. RICHARDS, OF I-IARTFORD, OON NEOTIOUT.

LI'HREIAD-CONTROLLING ATTACHMENT FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 613,475, dated November1, 1898:, Application filed February 3-. 1898. Serial No. 6691008. (Nomodel.)

To all whom it may concern.- H

Be it known that I, FRANCIS H. RICHARDS, a citizen of the United States,residing at Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inThread-Controlling Attachments for Sewing-Machines, of which thefoll-owing is a specification.

This invention in sewing-machines relates more particularly to athread-controlling attachment of the genus described in mycontemporaneously-pending application, Serial No. 675,335, filed March26, 1898, to which reference may be had.

The object of my present invention is to.

provide a simple and efficient thread-controlling device which may bereadily attached to or removed from the needle-bar of a sewingmachineand which will not only constitute a guide for, but will alsoautomatically clamp, the needle-thread at a point in close proximity tothe needle and positively hold that portion of the needle-thread locatedbelow the eye of the needle against retractive or backward movementwithout retarding or obstructing the advancing movement of said thread.

A further object of my present invention is to provide, in connectionwith the needlebar of a sewing-machine, a controlling device comprisinga bracket having two remote thread-guides and also having intermediateof said guides two opposing wedge-faces, oneof which constitutes a bedfor supporting the thread, and a thread-clamping roll supported betweenthe wedge-faces and adapted for rotative movement and also for movementtoward and away from the apex of the plane of the wedge-faces.

In the drawings accompanying and forming part of this specification,Figure l is a front view of the lower part of the head of asewing-machine, together with the presser-bar, needle-bar, and needle,with the improved thread-controlling attachment removably secured to thelower end of said needle-bar. Fig. 2 is a side view of the parts shownin Fig. 1 as seen from the right in said figure. Fig. 3 is a plan View,on a relatively large scale, of the thread-controlling attachment inconnection with the needle-bar, said needle-bar being shown incross-section. Fig. 4:.

is a side view similar to Fig. 2, on a relatively large scale, of thethread-controlling attachment, a portion only of the needle-bar andneedle being shown; and Fig. 5 is a vertical cross-sectional view takenin dotted line a a, Fig. 4, showing the parts at the right-hand of saidline. Y I Y Similar characters designate like parts in all the figuresof the drawings.

In the accompanying drawings only so much of a sewing-machine is shownas is considered necessary to illustrate the construction, application,and mode of operation of my present improvements, and it will be un-.

derstood that the thread-controlling attachment which constitutes thesubject-matter of my present invention is applicable in various ways todifferent kinds of sewing-machines. It is, however, more especiallyadapted for that class of sewing-machines in which it is necessary toform a loop from the needlethread for the looper or shuttle to engageand in which it is necessary to prevent indrawing of said loop after thesame is formed and is expanded during the first stage of the upstroke ofthe needle.

In sewing-machines generally, and especially in those in which the loopof the needlethread is formed on the downstroke of the needle and isspread sidewise or distended during the first stages of the upstroke ofthe needle to condition the same for engagement by the looper, it hasbeen found in' practice that on the beginning of the upstroke of theneedle the needle-thread, being up to this time drawn taut and underconsiderable tension above the needle-eye, has a tendency to draw up orretract that portion of said thread located below the needle-eye, saidthread, owing to this tension, being drawn backward as soon as thedownward-pulling stress of the needle-thread is released by thebeginning of the upstroke of the needle, thus drawing in or reducing thesize of the loop formed below the work tosuch an extent as to preventits engagement by the hook of the looper, .causing the stitch mechanismfrequently to drop stitches and impairing the value of the Workproduced.

To obviate the disadvantage above recited, I have provided an improvedthread-controlling means adapted to be secured to a needlebar,preferably at the lower end thereof, in close proximity to the needleand consequently in close proximity to the upper side of the fabric whenthe needle has passed through the same and is about to begin itsupstroke,and which thread-controlling means is constructed and organizedto engage the needle-thread and hold the loop against retractivemovement during the first stages of the upstroke of the needle and untilsaid loop is engaged by the looper.

The thread-controlling attachment, in the preferred form thereof, (shownin Figs. 1 to 4 of the drawings,) comprises two cooperativethread-controlling members, (designated in a general way by G and 0,respectively,) one of which is in the nature of a thread guiding andsupporting bracket and embodies means whereby the same may be secured tothe needle-bar and the other of which is in the nature of a clamp-rollsupported for rotative and transverse movement on the bracketintermediate the guides and is adapted to cooperate with said bracketfor holding the needle-thread normally against retractivemovement-,while permitting, under a predetermined stress, a freeadvancing movement thereof.

The thread-controlling member or bracket 0, in the preferred formthereof, (shown most clearly in Figs. 3 and 4,) comprises the main bodyportion 2, terminating at one end in a sleeve or hub 3, having aninteriorly-threaded boss at one side thereof and which sleeve or hub isadapted to encircle the needle-bar and be movably secured thereto by anysuitable fastening device, said fastening device in the present instanceconsisting of a set-screw 4, extending through the threaded portion ofthe hub, the inner end of the shank of the set-screw being preferably ofreduced diameter and extending through a smooth bore 5 in the needle-barand engaging the needle N and holding this in place, as well as holdingthe member C in place on the needle-bar.

The main body portion 2 of the bracket or member C is shown as havingtwo oppositely-disposed arms 6 and 7, one, 6, of which projects upwardand is provided at its outer end with a loop or thread guide 8, and theother, 7, of which projects downward and is provided at its outer endwith aloop or thread guide 9, said thread-guide 9 being so disposedrelatively to the needle N that that portion of the needle-thread Tlocated between the eye of the needle and the last-mentionedthread-guide 9 will lie parallel to the path of movement of said needle.

Formed upon one side face of the body portion 2 of the bracket,substantially midway between the two thread-guides 8 and 9,are twoopposing flanges 10 and 12, which flanges are located one above theother and have their adjacent faces inclined one relatively to theother, the space between said flanges constituting a runway 13,converging toward the outer end of the bracket or member 0, as will beunderstood by reference to Fig. 4 of the drawings.

The other controlling member 0 is shown in the nature of a roll or disksupported between the wedge-like faces of the two flanges 10 and 12.This clamp roll or disk is supported in the runway 13 and is held inplace preferably by a resilient roll-actuator, (designated in a generalway by 0 which in the present instance is shown as a substantiallyU-shaped spring coiled at the bend thereof and having one end bentinwardly, as shown at 14, and seated in a recess in the body portion 2of the bracket and having the opposite end thereof bent inwardly, as at15, and seated in a recess formed in the outer face of the clamp-r0110,as shown most clearly in Fig. 5.

By reference to Figs. 3 and 4 of the drawings it will be seen that theend 14 of the rollactuator c is located considerablyin advance of thatportion 15 of said actuator which supports the roll 0, and in practicesuch spring will be so formed and tempered as normally to force the roll0' toward the contracted end of the runway in which itis seated tothereby bring the working face of said roll into cooperative relationwith the bearing-face of the lower flange 12, which flange constitutesthe intermediate support for the needlethread T.

By supporting the rotative clamping mom ber of the thread-controllingattachment between the wedge-faces of the two flanges 10 and 12 in themanner described and providing a resilient actuator for normallyretaining the opposite portions of the working face of said roll inoperative relation with the ad jacent faces of said flanges saidactuator operates, after the manner of a tension device, to create atension between the working face of the roll and the thread supported onthe thread supporting flange, and holds said thread under more or lesstension, according to the stress exerted by the roll-actuator, whichtension may be varied by employing roll-actuators capable of exerting agreater or less stress upon the roll.

In threading the machine the upper or needle thread is first passedthrough the upper thread-guide 8, thence between the working face of theroll and the bed or supportingflange 12, thence through the lowerthreadguide 9, whence it is carried downward parallel to the axis ofmovement of the needle and passed through the eye of said needle.

By reference to Fig. 4 of the drawings it will be seen that the workingfaces of the opposing flanges 10 and 12 are so disposed to each otherand to the clamp-roll that said roll bears upon the lower flange or uponthe thread supported upon said flange at a point between the axis ofsaid roll and the outer end of the bracket 0 and that it bears againstthe upper flange at a point intermediate its axis and the axis ofmovement of the needle, so that when a pulling stress is exerted uponthe needlethread from below'the bearing-point of the roll that portionof the needle-thread between the two thread-guides 8 and 9 will act uponthe bearing-point of the roll at one side of the vertical plane of theaxis of said roll and in a line intersecting the axis of movement of theneedle-bar and will force said roll backward toward the needle-bar andout of close relation with the lower thread-supporting flange, theresistance of the actuator determining the tension exerted upon thethread at this point and consequently the stress required for drawingthe roll backward to overcome this tension and release saidneedlethread.

The stress exerted'by the roll-actuator for retaining, the roll inworking engagement with the thread-supporting flange will in practice beslight, so as not materially to interfere with the drawing out of theneedle-thread from above the controlling device during the formation ofsuccessive loops in sewing.

By reference to Figs. 3, 4:, and 5 it will be seen that theroll-actuator is so constructed as to press the inner face of the rollinward against the side face of the inner wall of the runway 13, thefriction of these parts retarding the rotative movement of the rollsufficiently to decrease to a considerable extent the momentum of theroll.

Having described my invention, I claim 1. A thread-controllingattachmentfor a sewing-machine, comprising a bracket having a thread-guide and twooppositely-inclined flanges, and a rotary thread-clamp supportedintermediate said flanges.

2. A thread-controlling attachment for a sewing-machine, comprising abracket having two remote thread-guides and also having a wedge-likerunway for a clamp-roll, and a clamp-roll supported intermediate thethreadguides in said runway'and organized to clamp a thread extendingthrough said guides between the perimeter of theroll and one face of therunway.

3. A thread-controlling attachment for a sewing-machine, comprising abracket having a thread-support or flange; a rotary threadclampsupported in operative relation with the thread-support and organized tohold the thread against retraction while permitting an advancingmovement thereof; and an actuator in connection with said thread-clamp.

4. A thread-controlling attachment for a sewing-machine, comprising abrackethaving a thread-support or flange; a rotary threadclamp supportedin operative relation with the thread-support and organized for rotativeand longitudinal movement relative to said support and adapted fornormally holding said thread against retraction while permitting anadvancing movement thereof; and a resilient actuator in connection withsaid thread-clamp.

5. The combination, with the needle-bar of a sewing-machine, of twothread-controlling members, one of which is in the nature of a bracketand is fixed to the needle-bar and has two oppositely-inclinedflange-faces, and the other of which is in the nature of a rollshiftably supported between and in operative relation with theflange-faces; and a resilient actuator in connection with said roll.

6. A thread-controlling attachment for a sewing-machine, comprising abracket having a sleeve for encircling the needle-bar of a sew=ing-machine and also having a thread support or bed; a rotarythread-clamp supported in position on said bracket to engage the threadon its passage through said bed and operable for preventing theretraction thereof; and fastening means in connection with said sleeveand adapted for securing the bracket in position on the needle-bar.

7. The combination, with a sewing-machine needle-bar carrying a needle,of a thread-controlling attachment comprising a bracket havin g a hubencircling said needle-bar and also having two oppositely-extending armseach provided with a thread-guide at the outer end thereof, and a threadsupport or bed intermediate said thread-guide; means for securing thebracket'in position on the needle-bar;

a rotary thread-clamp supported for movement longitudinally of the bedand in the plane of the thread supported thereon; and a resilientactuator in operative connection with, and adapted for normally forcing,the thread-clamp into close relation with the thread-supporting bed.

FRANCIS H. RICHARDS.

IOO

